All around the foundation wall there was staining consistent with the staining you see here.

You can see from the different lines that the water level happens regularly, and at different heights.

It had not rained in many days previous to this inspection, but there were still puddles here and there on top of the plastic vapor retarder, dried stains on the plastic from other puddles, and very soft spots all over underneath.

This is a crawl space that gets very wet, and often! And apparently this has gone mostly unnoticed, and for years. The grading and drainage outside this house was not good, although on one side there were very recent changes to two downspouts.

This continued water infestation will contribute to an increase in relative humidity levels in this crawl space, levels that may often be higher than the relative humidity outdoors, and in turn contribute to the relative humidity inside the house.

That can affect and cause many things including: the interior air quality, the function of the insulation under the floor (in this house there was very little insulation under the floor!), the humidity inside the house, the attraction and amplification of mold, fungi and yeast development, the attraction of mites that feed on fungi, die and then become food for further fungi development, the invitation to termites and other wood-destroying insects, other wood-destroying micro-organisms, damage to paint and wallpaper inside the house, and even rot in certain structural materials like wood beams.

My recommendation: grading and drainage is a crucial aspect of landscaping and home maintenance. Grading is often neglected! Downspouts and sump pumps MUSTdischarge water well away from the house, and onto areas that are inclined away from the house ideally at 1/2" per foot. Water is most damaging, and THE killer of houses inside and out.